Share this:

Like this:

I have been very ill for a couple of years. It impacts my cognition as much as it impacts my physical abilities. I have to take some time off from blogging to rest and to attend to pressing matters, as my life is full of doctors, lawyers, and other expensive people. Read the rest of this entry »

The purpose of the article about changing the anode resistor value was to improve the clean channel and smooth the dirty channels. That is exactly what it will do, but I wanted to talk about conceptual ideas regarding this change. I’m going to use pedals for illustration and then translate that over to tube amplifiers.

Analogy

I used to build guitar pedals and I’ve spent a lot of time cascading circuits into each other. While transistors and op amps react differently than tubes, the overall result on dynamics is similar from one component to another. Read the rest of this entry »

Basics of the Signal Path

The input to the Boss GE-7 Graphic EQ has a buffer which is active at all times. There is a slight emphasis around 2 kHz to help the guitar sound stand out. Immediately after the buffer is the amplifier for the level control. It’s a differential type with only one source voltage split with the level’s sliding potentiometer. This slider will either boost or cut the whole signal when it is moved from the zero line. From here, the signal is split; one path goes to the EQ section and one part goes to the positive input of another differential amp. The EQ section feeds the negative input of the differential amp. Read the rest of this entry »

Share this:

Like this:

I was watching the Steve Morse Rig Rundown at Premiere Guitar. Steve stated that he uses the Neck pickup to solo in the higher pitches, so it isn’t as sharp on a person’s eardrums. I’d never really thought of it in that way and not used it in that way very often. So, I tried it out repeatedly. Read the rest of this entry »

I had just a few thoughts come to mind regarding modifying amps, modifying EQ, or creating your own.

It’s a fact that Mesa Engineering uses two modified forms of the Marshall tone stack for their Dual Rectifier series. Compared to a classic Marshall tone stack, the Vintage/Raw tone stack moves the center of the “Mid” control down in frequency and has more attenuation. This carves out some of the meatier part of the guitar frequency to make room for the massive lows and a high-mid emphasis. The tone stack enabled for Channel 3 Modern has boosted upper-mids, but has a very similar, low-to-low-mid frequency response. Read the rest of this entry »

I put together a rudimentary representation of the effect on filter curves when setting a graphic EQ. It isn’t exact. Use it to get a general idea for the way a graphic EQ shapes the signal. Read the rest of this entry »

Using an equalizer to boost the guitar’s input signal makes a lot of sense. It provides a clean gain and a lot of headroom. Aside from boosting the signal, it can, of course, be used to carve out specific frequencies. Unlike most overdrive pedals, an equalizer has the ability to be very precise with multiple frequency bands and can create special effects.

The downside to this specific pedal is noise. It uses cheap tantalum capacitors in the signal path. This creates a hissing sound when the sliders are moved away from the zero mark. The MXR 10 Band EQ is reputedly better, but I don’t own it and can’t comment about it further. Read the rest of this entry »

On the back of every Mesa Engineering Dual Rectifier, there are 2 switches to select options for the power supply. One of these is to select Bold and Spongy and affect overall voltage to the amplifier, with Bold being full power and Spongy reducing power by about 20%. The other switch is used to select the rectification: Silicon or Tube. Selecting Tube reduces power by nearly 10%, since the tube has losses when it conducts. There are 4 options for running the power supply:

Bold and Silicon

Bold and Tube

Spongy and Silicon

Spongy and Tube

Before I get to decisions for selecting power supply options, we should cover some facts and history. Along the way, we’ll learn basic information about the differences between these options. Read the rest of this entry »

Share this:

Like this:

I occasionally re-read my blog articles and wonder if I was hallucinating in a fever dream while typing poorly translated incantations. It looks like words arranged into sentences, but it doesn’t make a lot of sense. I’ve been updating some of them so they aren’t as confusing, or, in some cases, so they actually make sense.

The truth is that I often write while having morning coffee. Perhaps I should wait until after morning coffee?